Refrigerating apparatus



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" 7 REFRIGERATING APPARATUS Fi'ed lay 29, 1936 2 Sheets-Sheet l I VENTOR BY I 1 19'. l

A'ITORNEYS Feb. 13, 1940, F. SMITH REFRIGERATING APPARATUS Filed lay 29, 1936 2 Sheets-Sheet 2 INVENTOR.

BY I ATTORNEYS Patente'd Feb. 13, 1940- UNITED STATES REFRIGERATING APPARATUS Harry F. Smith, Dayton, Ohio, assignoto General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application May 29, 1936. Serial No. 82,551

Claims. (o. tia-#140) r This invention -relates to refrigerating apparatus and more particularly to driving' devices tor driving the circulating means which circulates the medium to be cooled into heat exchange 5 relation with the evaporating means.

In small present-day room coolers, there is ordinarily provided an .enclosed machine compartment which contains a motor-compressor unit and often a water cooled condenser. However, the condenser is sometimes placed outside of the machine compartment, outside of the room to be cooled. such room coolers also have another compartment containing an evaporating means and provided with a fan for taking the air from 'the room and circulating the air into heat exchange rlation with the evaporating means and again returning the air to the room. such fans, however, have ordinarily been driven 'by an independent electric motor. 4

It is an object of my invention to simplify the construction and reduce the cost of such room coolers by driving the circulating fan from the motor-compressor ,unit by an improved simplified form of driving means. 4

The machine compartment is ordinarily filled with warm air considerably above the temperature of the air in the room. Therefore, such com-` partments are ordinarilyenclosed and insulated. However, in order to place the circulating fan so outside the machine compartment and to drive it from the motor-compressor unit, it is necessary tor the driving connection topass through one of the walls of the machine compartment. It is, therefore, an object of my invention to provide a driving means for the' circulating fan which is provided with a seal to prevent the escape of warm air from the machine compartment into the room.

Further objects and advantages of the present invention will be apparent from 'the following description, reference being had to' the accompanying drawings wherein a preierred form of the present invention is clearly shown. In the drawings:

Fig. 1 is a vertical sectional view 'of a room cooler embodying my'invention;

Fig. 2 is an enlarged sectional view ot the circulating fan and uppr portion of the driving connection shown in Flg. 1;

' Fig. 3 is a horizontal sectlonal view through a portion of the driving connection in the machine compartment; and

Fig. 4 is a vertical sectional view through the pulley showing it in contact with the belt oi the motor-compressor unit.

Briefly, I have shown a room cooler with an insulated enclosed machine compartment in its lower portion containing a liqueiying apparatus including a reciprocating compressor driven through a V-belt driving connection by an elec- 5 tric motor. This machine compartment also includes a water cooled condenser and a cooler for the air of the machine compartment. Above the machine compartment is an evaporator compartment and above the evaporating means is a cir- 10 culating fan located in the outlet of the evaporator compartment for drawing air through the evaporating means from the room and again discharging the air to the room.

In the machine compartment is a pulley which 15 rides upon the top of the V-belt andwhich is connected by a flexible shaft which extends through a casing horizontally and upwardly to the circulating fan. This pulley is held in contact with the top of the belt by a pair of spaced 20 spring metal strips. The casing of the flexible shaft is sealed by the rubber bushing at the point where it passes through the insulated top wall of the machine compartment. Within the evaporator compartment, the casing of the flexible shaft 25 V is covered by sponge rubber tubing to prevent the transfer of noise, as well as to prevent leakage from the drip' pan. I i

Referring now to the drawings'and more particularly to Fig. 1, there is shown a room cooler 30 generally designated by the reference character 20 and provided with an angle iron framework 22 which is enclosed by outer metal panels 24 which form the outer vertical walls of the cabinet. These panels have a top member 26 resting upon 35 their upper edges which forms the top of the cabinet. In the lower portion of the room coolers, there is provided a machine compartment 28 which is' formed by slabs 32, 34, 36 and. 38 'on the sides, bottom and top of the compartment. 40 a .These slabs are of some suitable insulating material having some structural strength and are fastened to the rame of the cabinet. Within the machine compartment 28 is a metal framework 40 which forms the base of the compressor unit. This base is supported preferably v through a resilient vibr'ation absorbing supporting means from the framework of the cooler. This base 40 supports a reciprocating compressor 42 provided with a relatively large V-type fly- 50 wheel pulley 44 which receives a v-belt 46 which in turn extends over a v -pulley 48 upon the electric driving motor 50. 1 The electric motor 50 through its pulley 48, the elt 46, the compressor pulley 44 drives the compressor to compress evaporated refrigerant and forward the compressed refrigerant through a conduit 52 to a water cooled condenser 54 where the refrigerant is condensed and collected.

The liquid refrigerant which is condensed within the condenser 54 is then forwarded through a supply conduit 56 to a thermostatic automatic expansion valve 58 which controls the supply of liquid refrigerant to the evaporating means 60. This evaporating means 60 is positioned transversely in a compartment 62 located immediately above the machine compartment 28 and provided with an inlet opening 64 beneath the evaporating means 60. The top of this 'compartment 62 is provided with an outlet opening 66 directly above the center of the evaporating means 60.

This outlet 66 receives a circulating' fan 68 of a rather unusual type which is relatively highly efflcient for this type of service. This circulating fan 68 draws air from the room into the com- 'partment 62 through the opening 64 and then draws the air upwardly between the flns and conduits of the evaporating means 60 and thence through the opening 68 into a discharge chamber 10. This chamber 10' is lined with a sound absorbing and insulating material 12 which extends upwardly into scaling engagement with the top member 26. The top member 26 is provided with a. grilled outlet opening 14 directly above the fan 68. The grille for this outlet opening 14 has blades positioned`at a 45 angle so as to throw the air upwardly at an angle above the heads of the occupants of theroom so as to avoid any direct draft upon any occupant. The `'air from the room so circulated is cooled by the evaporating means 60 which also condenses moisture from the circulating air and thereby reduces its moisture content. In this process, the liquid refrigerant in the evaporating means absorbs heat and evaporates under reduced pressure and this evaporated refrigerant is returned to the compressor through the 'return conduit 16. Directly beneath the evaporating means 60 is a drip pan 18 supported by the framework of the cabinet for collecting moisture which condenses upon and drips from the evaporator 60. This drip pan 18 is provided with some suitable form of drain or other suitable form of water disposing means.

Within the machine compartment 28 is a finned heat absorbing member provided with serpentine tubes which first receive the water for cooling purposes through the 'conduit 82. This heat absorbing member 80 absorbs heat from the air which is circulated within the machine compartment by a fan 84 provided upon the motor 50 adjacent the pulley 48. From the heat absorbing unit 80 the cooling water then passes through the conduit 86 to the water cooling coil 88 in the condenser 54. The outlet of this water cooling coil 88 is connected to a thermostatic control valve 90 which has a control element provided with a tubular connection 92 which connects to the compressor discharge conduit 52. This provides a control of the circulation of cooling water according to the' so-called head or condenser pressure. l

Heretofore, thecirculating fan for circulating the air in heat exchange relationship with the evaporating means has been driven by a separate electric motor provided in a compartment such as the compartment or chamber 10. It has also been p'ropsed to drive such a fan through an ordinary pulley and belt from the motor-compressor unit. However. such a belt drive does not V appear to have proved practical, probably because of the necessity of preventing the escape of warm air from the machine compartment 28 into the room. While the use of a separate electric motor for the circulating fan provides Satisfactory performance, it necessitates that an electric motor, in addition to the compressor driving I such apparatus.

;I have, therefore, provided an improved form of driving device which is capable of driving the circulating fan 68 from the motor-compressor unit, while at the same time, it does not provide 'an avenue for the escape of warm air from the machine compartment into the room. In this driving device, there is provided a pulley 94 which rests upon the top of the V-belt 46 and which is connected to a triple or quadruple wound flexible shaft which extends through a flexible metal casing 96, at first horizontally and then upwardly through an aperture 98 in the insulating slab 38 through a flanged aperture l02 in the drip pan 18 and thence between the center fins of the evaporator 60 up to a three arm spider bracket l04 located directly beneath the opening 66 between the compartments 62 and 10. This bracket |04 supports the fan 68 which is fastened to the upper end of theflexible shaft.

The aperture 98 in the insulating 'slab 38 is sealed by a tapered flanged rubber bushing 106 which provides a seal between the slab and the casing 96 of the flexible shaft. In order to prevent the transfer of noise from the flexible casing to the evaporating means 60 and to the circulating air, I provide an insulating casing for the casing 96 of the flexible shaft. This insulating casing 108 is in the form of sponge' rubber tubing and receives the portion of the flexible casing 96 between the bracket |04 and the dripcpan 18 and particularly has its lower end extending over the upper edge of the flanged aperture |02 to prevent any moisture 'from passing downwardly along the flexible casing 96 below the drip pan 18. This casing |08 insulates the casing 96 of the flexible shaft from the evaporating means 60 so that heat andnoise from the flexible shaft will not be transmitted through metallic contact with the evaporating means 60 which would otherwise transmit the noise to the circulating air. i

Referring now more particularly to Figs. 2, 3 and'4 for a detailed construction of my improved driving device, there is provided a bracket |I0 'having a notch ll2 which receives one of the ,cooling fins of the compressor body while an compressor body by any of the usual forms of mounting such as by screws or bolts to. some convenient part of the compressor. This bracket is provided with two spaced tapered spring metal leaf springs l|6 and l|8 which are fastened to the upper and lower faces of an arm of the bracket by screws. These two leaf springs extend in the same direction from the bracket l|0 and are fastened by 'screws to the upper and lower faces of an arm !20. This arm extends from a sort of a bell-shaped portion of a member !22 which' receives the lower end of the flexible casing. v

The reduoed end of this member !22' is provided with a support for the inner portion !24 of a ball bearing. The outer portion !26 of the ball hearing is received within the hub !26 of the pulley 94. This hub !29 is provided with a boss which receives the lower end of the flexible shaft !32. This flexible shaft !32 is preferably made of' spring wire wound in opposite directions and having three or four layers of wire. This form of ilexible shafting is practically universally used for speedometer drive and serves this purpose admirably. It, however, has the disadvantage that it cannot`transmit a great amount of torque and particularly should not be subjected to sudden torque loads. This flexible shaft is held to the hub !30 by a set screw !34. The springs !!6 and !!8 hold the pulley 94 in contact with the upper face of the belt. However, as will be seen best in Fig. 1, the pulley 94 has only a small portion of its periphery in contact with the belt at any one point and, therefore, only a relatively small torque will be transmitted to the pulley and the flexible shaft from the belt.

The driving motor 50 ordinarily operates at `from 1700 to 1800 R. P. M. The pulley 94 on the other hand operates at only from 800 to 1200 R. P. M. This speed can readily be controlled by the size of the driving pulley 94. The flexible shaft !32 with its flexible metal casing 96 can readily accommodate the movement of the member !22 as necessary to keep the pulley 94 in contact with the upper portion of the belt. This pulle`y"94 will be subject to considerable movement because of the varying tension upon the upper portion of the belt under starting conditions and difierent forms of load conditions. The arm and the spaced leaf springs !!6 and !8 take care of the torque reaction involved .in driving the 'pulley from the belt as well as hold the pulley in contact with the belt.

The upper end of thecasing 96 of the flexible shat is received within a threaded bushing !36 and fastened thereto either by a press fit or by a solder connection. This bushing !36 is threaded into another bushing which fits tightly within the hub !40 of the spider supporting member !04. This hub !40 is-provided with a recess !42 surrounding the upper portion of the bushing !38. This recess receives' the lower portion of a sort of a. funnel-shaped member !44. This funnel-shaped member !44 and the recess !42 are provided with oil designated by the reference character !46. r

The bushing !38 receives the lower end of a 'hollow shaft or sleeve !48 which extends upwardly within the hub !50 of the circulating fan 60. This hub !50 is fastened to the sheet metal plate portion of the fan by cap screws !52. This hub !50 is also provided with lower and upper .porous bearing bushings !54 and !56 which are' the upper hearing so as to provide lubrication for the bushings !54 so that the hub !50 may rotate with little friction upon the sleeve !48. This wick does not lie within the plane of the sections and therefore does not appear in the drawings. The lower portion of the bushing !54 rests upon a th-ust collar or washer !58 located within 'the oil and resting upon the upper face ot the bushing !36. The upper end of the hub is provided with a cap !60 i'astened to it by a. set screw !62 and fastened to the upper end of the `flexible shatt which extends through the sleeve !46 by a second set screw !64.

This driving device is simple, convenient and free from many troubles of mis-alignment. It is not only advantageous in the specific application disclosed herein, but also in many others.

While the form of embodiment of the present invention as herein dlsclosed constitutes a preferred form, it is tobe understood that other forms might be adopted, all coming within the scope of the claims 'which follow.

What is claimed is as follows:

1. Refrigerating apparatus including a cabinet including a machine compartment and an evaporator compartment, a motor-compressor unit in the machine compartment, an evaporating means in the evaporator compartment, a condenser cperably connected to the evaporator and compressor, a fan for circulating air in heat exchange relation with the evaporating means,

means including a flexible shaft extending from the motor-compressor unit to said fan, and torque limiting means for limiting the amount oi' torque transmitted to the flexible shaft and said fan for/driving said Ian.

2. Rfrigerating apparatus including a cabinet located in a room to be cooled, having a machine compartment enclosed to prevent leakage of air from the compartment to the room, an evaporating means outside of said machine compartment, a motor-compressor unit within the enclosed machine compartment, a condenser connected in operative refrigerant circuit relationship with said evaporating means and said motor-compressor unit, a fan means outside said machine compartment for circulating air from the room in heat exchange relationship with the evaporating means, a driving connection extending from said motor-compressor unit through an aperture in the enclosure of said machine compartment to said fan, said aperture containing the drivingconnection being sealed to prevent the escape of air from the machine compartment, said driving connection including a flexible conduit and a fiexible shaft extending through said conduit from said motor-compressor unit to said fan, and 'means for limiting the amount of torque transmitted from the motor-compressor unit'to said flexible shaft.

- located in a room to be cooled, having a machine compartment enclosed to prevent leakage of air from the compartment to the room, an evaporating means outside of said machine compartment, a motor-compressor unit withir`r-the enclosed machine compartment, a condenser c erative refrigerant circuit relation ip with said evaporating means and said mot r-compressor unit, a fan means outside said mac ine compartment for circulating air from the room in heat exchange relationship with the. evaporating means,

and a driving connection extendlng from saidmotor-compressor unit through an aperture in the enclosure of said machine compartment to said fan, said aperture containing the driving connection being sealed to prevent the escape of air from the machine compartment, said driving connection including a pulley having its rim in contact with a movable portion of said motorcompressor unit, said pulley being provided with spring means for holding it in contact with the movable portion at a certain tension to limit the nected in opamount of force transmitted to the pulley, said driving connection including a fiexible shaft extending from said pulley to said fan.

4. Refrigerating apparatus including a cabinet located in a room to be cooled, said cabinet having a machine compartment, an evaporator com- A partment located above the machine compartment, the top wall of said evaporator Compartment being provided with an aperture, a fan disposed substantially within said aperture and having a vertical axis of rotation,` a motor and compressor located within the machine compartment, said motor and compressor being connected by a belt drive, a pulley with a horizontal axis having its periphery in engage'ment with the belt drive, spring means for keeping the puiley in contact with the belt drive, and a flexible shaft connecting said pulley and said fan.

5. Refrigerating apparatus including a cabinet located in a room to be cooled, said cabinet having a machine compartment, an evaporator compartment located above the machine compartment, the top wall of said evaporator Compartment being provided with an aperture, a. fan disposed substantially within said aperture and having a verticalaxis of rotation, a motor and compressor located within the machine compartment, said motor and compressor being connected by a belt drive, a pulley with a horizontal axis having its periphery in engagement with the belt drive, spring means for keeping the pulley in contact with the belt drive, and a flexible shaft connecting said pulley and said fan, an evaporating means positioned horizontally within said compartment, a drlp pan located beneath -said evaporator, said drip pan being provided with an aperture having an upturned flange, said flexible shaft extending through the aperture in said drip pan and through said evaporator.

HARRY F. SMITH. sa 

